ARCHIVED REPORTS XR0012943 - Laserfiche WebLink

Home Browse Search

R604 :UPDATE 16 2-23-1993 in volt seconds, and assigns a peak number and retention time. The sum of all the responses are then used to obtain a mg/L per volt second calibrant factor. This factor is used to calculate mg/L as gasoline vapor from each analysis . Pounds per day can be computed using these mg/L values, and the pressure differential created at the orifice (flow rate) for each well, and total influent . Since September 25, 1992, tedlar bag samples are obtained and brought back to be analyzed in the WEGE portable laboratory. This is necessary due to long eluting time (analysis time increased from 10 minutes per sample to 30 minutes per sample) needed per analysis using the 10s50 (all early eluding compounds have been removed by vapor extraction) . The pounds per day values for each well and the influent are then averaged to the preceding site visit' s pound per day value and then multiplied by the number of days the system operated between visits to estimate the total pounds each well and the total system has removed for that time period. This poundage is then added to the accumulated poundage of the previous visit to update the total pounds removed to date, see Table 3 and Appendix B . Sampling Vapor Streams: The vapor samples are obtained by attaching a dedicated air tight soft polytubing to a sample port on the well side of the orifice plate on the vapor recovery manifold. The tubing is then connected to a tedlar bag placed inside a vacuum sampler. The sample port is then opened and the vacuum placed on the tedlar bag from the sample vessel allows the tedlar bag to fill with the vapor stream from that particular sample port . Once the tedlar �,. bag is full the valve is closed and the vacuum removed from the sample vessel . The tedlar bag contains an air tight locking septum valve which is then closed and locked to secure the vapor sample. A small dedicated needle attached to a dedicated 1 cc syringe is then inserted through the sample septum into the tedlar bag. The lcc syringe is purged numerous times before filling it with the sample. All but 0 . 5 cc of the sample is ejected into the air before injecting the remaining 0 . 5 cc syringe sample into the Shimadzu FID-GC (the calibrant injection is 0 . 5 cc) . Once the chromatogram is recorded, an instrument blank is run prior to the next sample. The instrument blank will indicate if residual peaks are being carried onto the next analysis . Vacuum influent readings are obtained from the wells by attaching a manometer calibrated in mm water to sample ports at the well heads . These readings show the mm water pressure or vacuum that is being created at each well . page 5